A Study On Fatigue Reliability Of Jacket Platforms

The fatigue collapse is an important failure mode, especially for ocean-platform structure. There are many stochastic factors affecting their design. It includes material properties and dimensions, uncertain loads, calculation models and so on. So it is necessary that structures should be evaluated by reliability methods. Because of the progressive fatigue of elements, the reliability of structure will reduce as it is going. If the real reliability is less than regulated value, the structure is dangerous. Therefore , we should inspect and repair them. Main content of this thesis is as following:1. Based on the parameter modeling technology of ANSYS and APDL, the special analyze program of the jacket platform is exploited. According to the characters of the sea area, the jacket platform is analyzed by the dynamic structure. Modeling—Solving—Final processing.2. The program is proved by the factual data. Therefore, the way combined ANSYS is perfect. It is easy to model and solve. It is also more effective than modeling and solving by the classical approach.3. On the basis of the S-N model and the linear progressive damage theory, the jacket platform is analyzed by the reliability from the systemic point of views.